Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
An image forming apparatus such as a color copier and a color printer, which employs an electrophotographic method, includes a light scanning device. The light scanning device irradiates a plurality of charged image carriers with a light so as to form an electrostatic latent image on each of the image carriers. A housing of the light scanning device includes a housing portion with one opening surface and a cover portion covering the opening. The housing portion internally embeds a scanning optical system. The cover portion includes emission ports formed for respective lights emitted from the scanning optical system corresponding to each of the image carriers. Further, the emission ports are each covered with a permeable member. The permeable member has a permeability to the light emitted from the scanning optical system.
Each of the permeable members is located to prevent toner, dust, or the like from entering inside of the light scanning device. If the toner, the dust, or the like attach to a part of or the whole of a plurality of optical components, which are located inside the light scanning device, their optical properties may deteriorate. The deterioration of the optical properties causes deterioration of a quality of an image formed on a recording-target medium such as a paper sheet.
Meanwhile, the optical properties may deteriorate when the toner, the dust, or the like attach to a part of an outer surface or the whole outer surface of each of the permeable members. In view of this, the outer surface of each of the permeable members needs to be cleaned regularly, and for example, there is proposed an automatic cleaning mechanism that cleans the outer surface of each permeable member automatically. This automatic cleaning mechanism includes a plurality of screw shafts that are located along with a longer side direction of each of the permeable members, and each of the screw shafts moves a plurality of cleaning members in the identical direction simultaneously. Each of the cleaning members slides on the outer surface of corresponding permeable member. This makes each of the permeable members cleaned simultaneously.